As temps soar, cities promote ‘cool roofs’ for climate resilience Image By EPN Staff As record summer temperatures scorch urban centers, several U.S. cities such as Miami, Phoenix and Chicago are mandating cool roofs or reflective surfaces on new buildings to combat the urban heat island effect. Why it matters Cool roofs, which use light-colored or reflective materials, significantly reduce heat absorption. A U.S. EPA study finds that when widely implemented, cool roofs can directly reduce heat-related mortality by 18% and help cool ambient urban temperatures. In Phoenix, cool-roof retrofits on public buildings cut carbon emissions by nearly 28 metric tons annually and saved the city $106 million through energy efficiency programs like painting 10 million square feet of roofs. By moderating rooftop temperatures, cities can lower energy demand, improve air quality and bolster public health, especially in underserved neighborhoods hit hardest by heat waves. The bigger picture Cool roofing programs yield measurable energy and financial benefits. According to one modeling study, reflective roofs in Phoenix offer the highest savings; around $0.48/m² per year, outperforming Miami and Los Angeles. Nationally, switching to light-colored roofs could save approximately 10 TWh annually, equivalent to roughly 3% of U.S. cooling electricity use. A growing number of cities are adopting these standards to reduce electricity consumption, curb emissions, and enhance resilience to extreme heat. Phoenix launches a $106 million cool-roof plan in 2017 involving 10 million square feet of white roofing, cutting energy use, emissions, and peak demand. Chicago offers incentives, including zoning and stormwater credits, for cool and green roofs. Chicago City Hall’s green roof saves close to $10,000 annually in energy-related costs. Miami and others are integrating cool roofing into building codes to mitigate nighttime and daytime heat, following the EPA’s urban cool guidelines. Additional context While upfront costs for cool roofing can be higher than traditional materials, cities are leveraging energy savings and grants to offset installation premiums. The EPA’s Cool Roof Compendium outlines ROI timelines and cost-benefit calculators for municipalities and property owners. Cities can also refer to a recent roadmap guide to decarbonizing public buildings, highlighting how energy efficiency upgrades can lower utility bills while cutting emissions.
